Fine timing measurement (FTM) is a procedure that allows a fixed, portable, or mobile wireless station (STA) to determine its distance from another STA through an exchange of data packets via a wireless data connection (e.g., Wi-Fi®). An FTM session is an instance of a fine timing measurement procedure between an initiating STA and a responding STA. During the FTM session, the distance between STAs can be determined from the length of time it takes for a data packet to travel between STAs and the speed at which the packet travels (the speed of light). An FTM session may include a negotiation, measurement exchange and termination processes.
Traditionally, FTM sessions have been public sessions with no security features. This can make them vulnerable to spoofing attacks in which a snooping STA hijacks an STA session by communicating with the initiating STA in the place of the responding STA. In some instances, this could result in the initiating STA exchanging private information, money, and/or other valuable information with the snooping STA.